The Doctor always seems to come to the rescue of humans in their time of dire need, but what about ponykind? In the crossover fan film Doctor Whooves and the Assistant, the Doctor arrives in Ponyville just in time for the Summer Sun Celebration ceremony, and teams up with Derpy Hooves to stop the machinations of Nightmare Moon.

Animated Created by one Ocarinaplaya (Edit: and written by Piercesmoulder and KeikoandGilly) Doctor Whooves and the Assistant is a multi-episode fan film that promises to show the secret role the Doctor played in the pilot episode of My Little Pony: Friendship is Magic. The first episode, in which the Doctor meets Derpy (here using her official name, Ditzy Doo) and explores some of the finer mysteries of pony existence (Just how do they grab things with those hooves?) runs a bit long, but the just-released second episode is more on point, bringing the Doctor to the Sun Celebration, where he realizes that something is very, very wrong.

Ocarinaplaya has some process images on his deviantART profile. Hopefully there will be another episode in a few months, but the whole endeavor might be worthwhile just for the credit image of pixellated ponies riding in the TARDIS.

Edit: I've been informed that, while Ocarinaplaya is responsible for the actual character animation, the audio is from an audio play by PeirceSmolder and Keikoandgilly. There are a total of five audio episodes which you can listen to on the series' Tumblr.